Grinder-spindle



C. G. OLSUN.

GRINDER SPINDLE.

APPLICATION mED MAY 8, 1920.

1,398,817, Patented Oct. 18, 1921.

UNITED STATES PATENT OFFICE.

CARL G. OLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO ILLINOIS TOOL WORKS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

GRINDER-SPINDLE.

Application filed May 8, 1920. Serial No. 379,737.

T 0 all lwhom it may concern:

Be it known that I, CARL G. OLSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Grinder-spindles, of which the following is a specification.

My invention relates to grinder spindles and similar devices, examples of which may be found in my issued Patent No. 1,232,714 granted to me July 10th, 1917, and my copending application, Serial No. 373,150 filed I April 12th, 1920.

lVhile grinding is not the only purpose to which a device of this character may be put, I shall nevertheless describe the device primarily as a grinder, for the reason that, owing to the high speed at which grinders are rotated, my invention is particularly applicable to them.

One of thefobjects of the invention is to provide a device which may be operated at hiojh speed without causing any transverse "i ration or shaking Another object is to provide a take up mechanism which will automatically compensate for wear andfor lengthening and shortening of the spindle due to heating and cooling consequent upon high speed and rest, and prevent both side play and end play of the spindle. Still another object is to provide means whereby the grinding wheel will yield outward (shift axially away from the housing) in case it is pressed too hard against the work. In my copending application the spring disks i which enable the spindle to yield axially are rotatable in unison with the spindle. One of the objects of my present invention is to obtain an analogous effect by means of spring disks which, though they may creep angulally, are virtually non-rotary. It is also my purpose to accomplish these desirabilities in a simple, economical and durable manner. Y

I accomplish my objects by the mechanism illustrated in the accompanying drawings in which- Figure lis an assembly view of the complete device in the form of a grinder spindle, the housing and some of the other parts being shown in axial section.

F ig. 2 is a sectional view on the line 2 2, Fi 1.

1ig.- 3 is a face view of one of the dished,

annular springs which form part of the take-up mechanism.

Like numerals denote like parts throughout the several views.

In the form illustrated, the housing 1 has annular end caps 2, 3 closing its opposite ends. Within' the housing near the forward end is a bushing 5 which is conically tapered at one end in such manner as to Hare outward and 'form a seat for the conically tapered portion 6 of the spindle 8. This sleeve or bushing may be secured in various ways, for example, it may make a press fit with the housing and thus be held frictionally as in the illustrated form. While not essential, a felt washer 9 may appropriately be interposed between the `end cap f 2 and the end of the housing, one of its functions being to encircle the spindle and Patented Oct. `18, 1921.

prevent dust from entering. In addition to the conically tapered portion the bushing has a cylindrical portion 10 which forms a bearing for the adjacent cylindrical portion of the spindle. i

.Abutting therear end ofthe bushing is va set of non-rotary, resilient, dished annular disks 12 which are arranged in pairs, concavity to concavity. These disks encircle the spindle, their inner diameter preferably being such as to permit them to slide freely along the spindle. The outer diameter of the disks may be varied. In the present case they are shown to be substantially equal to the inner diameter of the housing, but

freely 'movable in it.

Abutting the innermost disk is a sleeve 14 which fits slidingly within the housing and at the rear end abuts a ring 15 which `is also slidable in the housing and forms the outer member of a ball bearing; that is, it forms the outer ball race for anti-,friction balls 16. The inner ball race is formed by an inner ring 18 which is annularly grooved for accommodating the balls and enabling them to exert endwise thrust upon the spindle. Ring 15 is concave on the inside when viewed in axial section, with the result that it is able to exert endwise thrust upon one or the other of the two sets of balls. The inner ring 18 is held rigid on the spindle so as to move endwise in unison'withl it. This holding may be variously accomplished, but according lto the present design a shoulder 20 is formed upon the spindle to abut f in lthe housing Ito shift inward 'face in which it bears, wear.

may now-be-.rotated at high speed--even` one end of the ring, and the other end of the ring abuts a sleeve 21 which encircles the spindle and is held in contact with the' formof a grinding wheel 26. rIhe design of chuck here illustrated is the same as the' one shown in my said copending. application and therefore need not be described in de-l tail. The end of the spindle is counter bored to slidingly receive a holding sleeve 28 havving an annular flange 29 at the outer end for between it and retaining the grinding wheel The inner end the outer .end of the Spindle.

vof the sleeve has a longitudinal slot 30 adapted to receive the inner end of a pin 32 fastened to the spindle. This permits the sleeve to move lengthwise but prevents it from rotating. The sleeve "is held in place by a screw 34 which Screws into an internally threaded counterbore 35 in the spindle. This construction prevents the negative torque of the grinding wheel when in action, creating a tendency to unscrew the parts.

By preference the chuck spindle has a pair of flats 36 on the side to enable it to be engaged by a wrench when the nut 24 is being applied `or removed.

Operation: When the parts are assembled there is a slight space between the outer (left) end of the conical portion 6 of the spindle and theadjacent washer 9 or end cap 2. -There is also a space between the ball races 15, 18 and the end cap' 3. This admits ofI endwise movement of the spindle so as to permit the spindle (toward the right) as the conical portion 6 of the spindle, and the sur- The spindle up to 20 or 30thousand revolutions per minute, and no vibration will occur. The bushing 5 is stationary in the housing and the conical portion of the spindle is held closely seated in its conical bearing by the springs 12 which tend to force the sleeve 14 toward the right, Figs. 1 and 2. The sleeve,

acting under the pressure of the springs, tends to force' the outer ball race 15 axially in the same direction, and this urges the inner set of balls (the ones toward the left,

Fig. 1) in the same direction. This setof balls, being seated in an annular groove, urges the ball race 18 in the same direction (axially toward the right) and as the spin- The advantage of dle is secured to fit, the endwise pressure or thrust holds the conical portion 6 close to its seat. High speed rotation of the spindle causes it to heat appreciably, and this increases its length. Afterward, when the spindle comes to rest, itshrinks'to normal length. The resilient take up mechanism in my device compensates for this variation and tends to keep the spindle seated in its conical bearing. Furthermore, the construction not only prevents end play, but permits the grinding wheel to yield (move toward the left) lin case its convex surface is pressed too hard or fed too rapidly against the work. Of course'the grinding wheel may act on either its convex. or concave side,`but in the present constructionv the yieldin action occurs when the thrust of thewor r istoward the left, Fig. 1. The opposite case is illustrated in my aforesaid'copending application.

It will be noted that the bushing 6 has not only a conical bearing surface, but also a Lcylindrical bearing surface for the spindle. this is, as pointed out in my copending application, that the spindle will still have an acting bearing surface and be preventedfrom moving crosswise on those occasions when the conical portion of the spindle is not closely seated.

It' will be noted that the construction is extremely simple, 'the amount of machine work and 4threading being reduced. to a minimum. The end caps'2, 3 may be pressed in place and the bushing 5 similarly secured. As the disks 12 are all alike, they may be kept in stock and readily replaced if necessary, and the degree of resilience may be varied by either varying the. number of disks employed or the thickness of the metal7 of which they are made.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a device of the classI described, a housing having a conical thrust bearing near one end flaring outward, a spindle having a conical portion adapted to seat in said thrust bearing, non-rotary resilient disks encircling the spindle and adapted to be strained by the housing for yieldinglyrholding the spindle seated in the thrust bearing, and a ball bearing adapted to coperate with the thrust bearing to keep the spindle centered in the housing.

2. In combination, a spindle having a conical port-ion, a housing having a conical bea/ring for the conical portion of the spindle: a ring slidably mounted within the housing and forming a bearing for the spindle,- the ring being adapted to exert endwise thrust on the spindle, and a spring encircling the spindle'and having a stationary abutment at'one end and at the other end exerting pressure axially upon said ring to hold the 4conical portion of the spindle seated in its conical bearing.

3.,In a kdevice of the class described, a housing having a'conical thrust bearing near one end Haring outward, and having a supplemental bearing of constant diameter for preventing crosswise movement of the spindle when not seated in the thrust beary ing, a second bearing for supporting a distant portion of the spindle, one of the two bearings being fixed in the housing and the other slidable longitudinally therein, and one of said bearings being adapted to exert endwise relative movement between the spindle and the conical thrust bearing, and a spring interposed between two of said bearings for yieldingly holding the spindle seated in the conical thrust bearing.

4. In a .device of the class described, a housing having a conical thrust bearing near one end flaring outward, and having a supplemental bearing of constant diameter for preventing crosswise movement of the spindle when not seated in the thrust bearing, a second bearing of constant diameter for supporting a distant portion of the spindle, one of the two bearings being fixed in the housing and the other slidable longitudinally therein, and one of said bearings being adapted to exert endwise relative movement between the spindle and the conical thrust bearing, and a series of resilient concave disks interposed between two of said bearings for yieldingly holding the spindle seated in the conical thrust bearing,n said disks being arranged in pairs, concavity to concavity.

5. In a device of the class described, a housing having a conical thrust bearing near one end Haring outward, a spindle having a conical portion adapted to seat in said thrust bearing, resilient disks encircling the spindle and adapted to be strained by the housing, a ball bearing adapted to support one end of the spindle in the housing, said ball bearing being adapted to exert endwise pressure Von the spindle, said disks being adapted to act upon said ball bearing for yieldingly urging it in a direction tol hold the conical portionof the spindle seated in its bearing.

6. In a device of the class described, a housing having a `conical thrust bearing near one end lflaring outward, said thrust bearing being fixed against longitudinal movement, the housing having a supplemental bearing of constant diameter for preventing crosswise movement of the spindle whennot seated in the thrust bearing, a ball bearing 'for supporting a distant portion of the spindle, the outer ring of said ball bearing being slidable longitudinally in the housing and the ball bearing being adapted to exert endwise movement on the spindle for holding it seated in the thrust bearing, and a spring interposed between the thrust bearing and the bau bearing far yieldingly holdnear one end flaring outward, said thrustl bearing being fixed against longitudinal movement, the housing having a supplemental bearing of constant diameter, for preventing crosswise movement of the spindle when not seated in the thrust bearing, a ball bearing for supporting a distant portion of the spindle, the outer ring of said ball bearing being slidable longitudinally in the housing and the. ball bearing being adapted to exert endwise movement on the spindle for holding it seated in the thrust bearing, and a series of resilient concave disks interposed between two of said bearings for yieldingly holding the spindle seated in the i conical thrustbearing, said disks being arranged in pairs, concavity to concavity.

8. In a. -device of the class described, a

"housing provided with a conical thrust bearing, a spindle having a conical portion seating in said bearing, a ball bearing adapted to coperate with the thrust bearing for supporting the spindle, the ball bearing having two rings with anti-friction balls interposed between them, the inner ring fitting against a. shoulder on the spindle andthe outer ring being slidable'lengthwise in the housing, a spring based at one end upon the housing and at the other end upon one of ther-ings of the ball bearing, the ball bearing being adapted to transmit thrust endwise to the spindle, a pulley mounted upon the spindle, and a nut screwing on the spindle and adapted to press the pulley against the inner and an outer ring, the inner ring being fast on the spindle and the outer ring being slidable lengthwise on the inner surface of the housing, balls between the two rings, adapted to transmit endwise thrust from one to the other, and a set of non-rotary,'resili ent, dished disks encircling the spindle between thel two bearings and arranged concavity to concavity, said disks having a stationary abutment at one end of the set and at the other end of the set being adapted to exert endwise pressure on the outer slidable ring of the ball bearing to yieldingly hold the conica-l portion of the spindle seated in its bearing. I

In witness whereof I have hereunto sub- 

